Redox Reaction in Size-Controlled LixFePO4

Author(s):  
Atsuo Yamada
2004 ◽  
Vol 69 (2) ◽  
pp. 419-425 ◽  
Author(s):  
Katarína Gmucová ◽  
Jozef Orlický ◽  
Juraj Pavlásek

The redox reaction of the neurotransmitter dopamine at the carbon fibre microelectrode was studied by several electrochemical methods. It was found that under conditions usual in a living body, the diffusion current fullfils, within experimental errors, the behavior theoretically predicted by the Cottrell equation. Nevertheless, attention should be paid to the fact that unsupported or weakly supported conditions give rise to a non-Cottrell response of diffusion current. Moreover, similar changes were observed if the dopamine concentration was either lower such as several units of μmol l-1, or about 100 μmol l-1 or higher. The non-Cottrell behavior of diffusion current involves the nonlinearity of the dopamine calibration curve obtained by pulse techniques. The present work is aimed at pointing out that such behavior of the measured data could lead to misinterpretation of the obtained dopamine concentration. Similar features could be also achieved for the other catecholamines.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hwan-Seop Yeo ◽  
Kwanjae Lee ◽  
Young Chul Sim ◽  
Seoung-Hwan Park ◽  
Yong-Hoon Cho

Abstract Optical polarization is an indispensable component in photonic applications, the orthogonality of which extends the degree of freedom of information, and strongly polarized and highly efficient small-size emitters are essential for compact polarization-based devices. We propose a group III-nitride quantum wire for a highly-efficient, strongly-polarized emitter, the polarization anisotropy of which stems solely from its one-dimensionality. We fabricated a site-selective and size-controlled single quantum wire using the geometrical shape of a three-dimensional structure under a self-limited growth mechanism. We present a strong and robust optical polarization anisotropy at room temperature emerging from a group III-nitride single quantum wire. Based on polarization-resolved spectroscopy and strain-included 6-band k·p calculations, the strong anisotropy is mainly attributed to the anisotropic strain distribution caused by the one-dimensionality, and its robustness to temperature is associated with an asymmetric quantum confinement effect.


Author(s):  
Zahra Heydari ◽  
Ibrahim Zarkesh ◽  
Mohammad-Hossein Ghanian ◽  
Mahdokht H. Aghdaei ◽  
Svetlana Kotova ◽  
...  
Keyword(s):  

2021 ◽  
Author(s):  
Hualong Chen ◽  
Yajing Liu ◽  
Xuebo Cheng ◽  
Senbiao Fang ◽  
Yuli Sun ◽  
...  

2021 ◽  
pp. 2100274
Author(s):  
Shigehito Osawa ◽  
Kenichi Kitanishi ◽  
Maho Kiuchi ◽  
Motoyuki Shimonaka ◽  
Hidenori Otsuka

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 362
Author(s):  
Yabibal Getahun Dessie ◽  
Qi Hong ◽  
Bachirou Guene Lougou ◽  
Juqi Zhang ◽  
Boshu Jiang ◽  
...  

Metal oxide materials are known for their ability to store thermochemical energy through reversible redox reactions. Metal oxides provide a new category of materials with exceptional performance in terms of thermochemical energy storage, reaction stability and oxygen-exchange and uptake capabilities. However, these characteristics are predicated on the right combination of the metal oxide candidates. In this study, metal oxide materials consisting of pure oxides, like cobalt(II) oxide, manganese(II) oxide, and iron(II, III) oxide (Fe3O4), and mixed oxides, such as (100 wt.% CoO, 100 wt.% Fe3O4, 100 wt.% CoO, 25 wt.% MnO + 75 wt.% CoO, 75 wt.% MnO + 25 wt.% CoO) and 50 wt.% MnO + 50.wt.% CoO), which was subjected to a two-cycle redox reaction, was proposed. The various mixtures of metal oxide catalysts proposed were investigated through the thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), energy dispersive X-ray (EDS), and scanning electron microscopy (SEM) analyses. The effect of argon (Ar) and oxygen (O2) at different gas flow rates (20, 30, and 50 mL/min) and temperature at thermal charging step and thermal discharging step (30–1400 °C) during the redox reaction were investigated. It was revealed that on the overall, 50 wt.% MnO + 50 wt.% CoO oxide had the most stable thermal stability and oxygen exchange to uptake ratio (0.83 and 0.99 at first and second redox reaction cycles, respectively). In addition, 30 mL/min Ar–20 mL/min O2 gas flow rate further increased the proposed (Fe,Co,Mn)Ox mixed oxide catalyst’s cyclic stability and oxygen uptake ratio. SEM revealed that the proposed (Fe,Co,Mn)Ox material had a smooth surface and consisted of polygonal-shaped structures. Thus, the proposed metallic oxide material can effectively be utilized for high-density thermochemical energy storage purposes. This study is of relevance to the power engineering industry and academia.


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